Spark plug



Apr. 17, 1923.

F. ARAGOSE SPARK PLUG Filed April 2, 1920 Patented Apr. 1?, 1923.

car are BK ARAGOSE, OF NORTH ADAMS, MASSACHUSETTS.

- SPARK PLUG.

Application filed April 2, 1920. Serial No. 370,715.

7 '0 all whom it may con cern Be it known that I, FRANK ARAGOSE, a citizen of the United States, residing at North Adams, in the county of Berkshire and State of Massachusetts,'have invented certain new and useful Improvements in Spark Plugs, of which the following is a specification.

My invention relates to improvements in spark plugs for use in internal combustion engines and has for its object the provision of a novel construction whereby the usual disadvantages, consequent to the accumulation of oil and carbon on the electrodes of w the plug are eliminated.

A further object of my invention is the provision of a dual spark gap in the combustion chamber of theengine by the utilization of a single plug and without alteration go to the ignition system common to automotive vehicles, thereby effecting a more positive'and rapid ignition of the explosive mixture.

A still further object of my invention is to provide a combustion chamber within the body of the plug in restricted communication with the combustion space of the engine in which one of the pair'of electrode terminals, arranged in series, provides the combined function of ignition of the explosive mixture and also a condenser action for intensifying the spark of the other electrode terminals, with the minimum consumption of current.

My invention relates, further, to other novel details of construction and arrangement of parts hereinafter described and particularly set forth in the accompanying drawings wherein:

Figure 1 is a longitudinal sectional View of my improved spark plug showing the interior construction and the general arrangement of parts.

Fig. 2 a perspective view of the neutral M electrode supporting element, and

Fig. 3 a detached perspective view of the pair of electrodes and associated parts to show assembly.

Spark plugs as ordinarily constructed comprise an externally threaded metal body in which is mounted or formed. in piece therewith, the outer or grounded electrode and an inner electrode. insulated from the body usually by porcelain. and extending ea through a central bore in the body which it closely fits, projecting above the top thereof f(t)r connection of the wire from the distribu or.

The terminals of the electrodes forming the spark gap extend into the combustion space of the engine, and are almost constantly subjected to the burning products of combustion and oil during the operation of the engine. It will be readily understood that, after continued use, these electrodes become sooted or coated with particles of carbon, not only greatly retarding the passage of the current from one terminal to the other and thereby effecting a weak spark, but, which, unless cleaned at frequent intervals, will also operate to bridge the electrodes and cause a short circuit.

To obviate the above referred to disadvantages and to provide numerous advantages heretofore unattainable with spark plugs as at present devised, I construct a hollow body 1, with a combustion chamber 2, having converging walls 3, which extend to the restricted opening 4, adjacent the inner end of the plug and adapted to communicate with the combustion space of an internal combustion engine. A pairof depending spark gap terminals 5 are formed on the inner end of the body, adjacent the sides of the opening 4 leading to the combustion chamber 2, and extending into the combustion space of the engine. These terminals 5 are grounded through the casting 6 in which the body 1 of the spark plug is threaded by the screwthreaded portion 7.

A yoke element 8, formed with a tapered socket 9 at its lower extremity, and an internally and externally threaded nut 10 at its upper end, is threaded into a screw-threaded aperture 11 in the top of the body 1, so as to position it centrally between the walls of the combustion chamber 2. This yoke element 8 supports a pair of electrodes 12 and 13 centrally in the combustion chamber 2, and in rigid fixed relation one to the other to provide a spark gap 14: hereafter to be described.

The lower or neutral electrode 13 is preferably tapered from end to end, and is surrounded by a plurality of layers of mica or other suitable insulating material 15. which insulate the'electrode from its supporting ring 16, which is also tapered to seat in the correspondingly tapered socket 9 of the yoke 8 through which the electrode extends, and

projects to a point below the inner extremity of the body 1. An insulating shell 17 preferably formed of porcelain, surrounds the lower portion of the electrode 13, and the assembly is rigidly secured in the yoke 8 by a washer 18 and a lock nut 19, which latter is threaded and secured to the lower extremity of the electrode 13-. A cup-shaped terminal 20 has screw-threaded connection to the lower extremity of the electrode 13 and is positioned adjacent the spark gap terminals 5.

The upper or positive electrode 12, like the lower electrode 13, is preferably tapered, and is insulated from its supporting nut 21, through which it extends, by a plurality of layers of mica 22 or other suitable insulating material. The nut 21 is threaded into the nut 10 forming the upper extremity of the yoke 8, and a plurality of removable washers 23, interposed between the nut 21 and an annular shoulder 24 provided in the nut 10, determine the diameter of the spark gap 14:. A cylindrical insulating bushing 25 incloses the' outer portion of the electrode 12, and is clamped between the outer face 'of the nut 10 and a lock nut 26 threaded on the upper extremity of the electrode. A

'thumb nut 27 is also threaded on the upper extremity of'the electrode 12 and serves as a binding post to connect the usual'comluctor 28 from thedistributor (not shown) to the ositive electrode 12.

T e operation is as follows:

The plug is threaded into the usual screwthreaded aperture provided in the wall 6 of the cylinder, and the spark gap provided by the spaced terminals 5 and 20 extend into the'combustion space of the engine to function in the usual manner as is clearly shown in Fig. 1 of the drawing.

The body 1 of the plug is provided with a combustlon chamber 2 which communicates with the combustion space of the engine through the restricted opening 4, in which the finer products of combustion are compressed on each compression stroke of the piston. The spark gap 14, provided between the terminalsof the electrodes 12 and 13 and arranged in series with the spark gap provided between the terminals 5 and 20, functions to ignite the highly volatile gases in the combustion chamber 2 at the same time that the terminals 5 and 20 function to ignite the mixture in the combustion space of the engine. But the gases confined in the chamber 2. igniting more readily than the mixture in the combustion space of the engine, rush through. the restricted opening 4 and past the terminals 5 and 20 cleaning them of such deposits as may have collected thereon and assisting them in the rapid ignition of the mixture in the combustion space. This construction greatly assists in the starting of an internal combustion engine after it has been allowed to remain idle for some time as for instance, over night.

The gases compressed within the chamber 2 in the body 1 of the plug, after the ignition circuit has been broken, will remain therein due to the restricted opening a being at the bottom of the chamber 2 and for the further reason that the lighter gases seeking the highest point in the combustion chamber will be thus confined by the heavier gases in the combustion space below. Upon the completion of the circuit, the said lighter gases, surrounding the spark gap, will be instantly ignited. Some of the heavier and less volatile constituents of the gases may condense after the engine is cooled and trickle down the insulating shell 17 inclosing the electrode 13. In order to collect such condensation and reserve it for use in assisting the initial starting impulse of the engine, I provide a priming cup 29 in the terminal 20.

It will be further understood that by providing a spark gap (such as at 14:) in series with the main spark gap in the combustion space of the engine, a condenser action is set up in the electrodes 12 and 13 which greatly intensifies the spark between the terminals 5 and 20. It will be understood that the products of condensation, collected in the cup 29 adjacent the spark gap provided by the terminals 5 and 20, will readily ignite upon the completion of the ignition circuit on starting the engine. If, however, for any reason, ignition of the collected condensation does not instantly occur, as above stated. the gases confined in the chamber 2, being simultaneously ignited, will cause ignition of the collected condensation as the burning gases expand and rush through the restricted opening 4, and past the terminals 5 and 20, thereby insuring positive and instantaneous starting of the engine.

I do not limit myself to the specific details herein shown and described, reserving such changes as may be made b those skilled in the art, my invention helng subject to various changes and modifications without departing from the spirit of the invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is '1. The combination with an internal combustion engine. of a spark plug extending through a wall and into the combustion space thereof. said plug being provided with spark gaps positioned one on each side of said wall and further provided with a chamber adjacent the outer gap, a restricted opening leading from said chamber and into the combustion space of said engine adjacent the inner gap. whereby the gases exploding in the outer chamber are forced through said opening with high velocity and caused to contact the electrodes of the inner gap and purge the same, substantially as described.

2. The combination with an internal combustion engine'having a combustion space, a spark plug formed outside of said space with a combustion chamber having a restricted opening communicating with said space, and a pairof spark gaps arranged in. series and disposed one on each side of said restricted opening, substantially as described.

3. A spark plug provided intermediate its ends with a combustion chamber, a spark gap therein, a second spark gap adjacent the end of said plug and adapted to be positioned in the combustion space of an internal combustion engine, and means adjacent said second spark gap, adapted for collection of products of condensation, substantially as described and for the purposes set forth. I

4. A spark plug for internal combustion engines comprising a hollow body formed with a spark gap terminal, a yoke mounted in said hollow body, and a pair of relatively spaced electrodes carried by said yoke, one of said electrodes extending adjacent said spark gap terminal.

5 A spark plug for internal combustion engines comprising a hollow body, a spark gap terminal carried thereby, ayoke mounted in said hollow body, and a pair of relatively spaced electrodes carried by said yoke, one of said electrodes extending through said body for connection with an electrical circuit and the other extending adjacent said spark gap terminal.

6. A spark plug for internal combustion engines comprising a body formed with a,

restricted chamber adapted to communicate with the combustion space thereof, a grounded terminal carried thereby, an electrode insulated from and extending through said body into said chamber, and a neutral electrode insulated from said body and interposed between said grounded terminal and said electrode.

7. A spark plug for internal combustion engines comprising a body formed with a said body providing a plurality of spark gaps.

9. A spark plug for internal combustion engines comprising a body formed with a combustion chamberadapted to communicate with the combustion space thereof and electrodes mounted in said combustion chamber and arranged in series providing a plurality of spark gaps.

In testimony whereof I aflix my signature.

FRANK ARAGOSE. 

